Unit 4.2 Line of Best Fit

What is a graphical summary?

A way to view and analyze data without using too many words or numbers

Are graphic summaries simple or complex?

• Both!

• Simple like a line graph

• Complex as a complete data analysis

What is a common way to express a two-variable data set?

With a scatter plot

In a scatter plot, what would we add to see is there’s a trend?

A line of best fit!

What is a line of best fit?

• A straight line that can be added to a graph manually or, more precisely, using technology

• It is a line that best fits the trend of the data

Define scatter plot

A graph that uses points to show the trend (relationship) between two variables

In a scatter plot what is on the X axis and what is on the Y axis?

• X axis represents the independent variable

• Y axis represents the dependent variable

What is the difference between independent and dependent variables?

• Independent is the cause; it’s value is independent from the other variable

• Dependent is the effect; it’s value depends on changes in the independent variable

What is a common independent variable found on the X axis?

Time

Choose which is dependent and which is independent: hours of daylight vs. temperature

• Temperature is dependent

• Hours of daylight is independent

Using GeoGebra Spreadsheet, how do you make a scatter plot?

• Add your data to the spreadsheet

• From the top toolbar, choose “{1, 2}”

• From the drop down menu, chose “list of points”

• Press Create

On GeoGebra Spreadsheet, how do you add a line of best fit?

• Under the fourth tab at the top toolbar, scroll down and choose